SEOUL, May 27 (Yonhap) -- North Korea launched an additional short-range missile from its east coast Tuesday night, an official at the South Korean presidential office said Wednesday.

"The North appears to have launched a ground-to-ship missile into the East Sea shortly after 9 p.m. Tuesday," the official said, asking not to be identified. Pyongyang had launched two short-range missiles from its east coast earlier Tuesday, following its supposed nuclear test the day before.

Officials here believe the missile launches are partly aimed at preventing South Korean and U.S. reconnaissance planes from nearing the communist state to verify its claimed nuclear test.

Earlier reports said there were also signs of imminent missile launches on the North's west coast. The official at the presidential office said the North has yet to launch any missile from the west.